Multicolored Mosaic Tesserae Used in the Girmil Church, East Gerasa, Jordan: A Microfacial Analysis and Provenance Determination

The present research aims at investigating the provenance of the tesserae of the Girmil Church located to the southeast of Gerasa, north Jordan. Six colored tesserae representing the five colors forming the mosaic floor images were collected and investigated both macroscopically by lenses, and microscopically by a polarized-light microscope to determine their lithology and microfacies. The six samples are two tesserae of a very pale brown (white) color of two sizes and four tesserae of yellow, strong brown, bluish black and dusky red colors. Because of the absence of geochemical databases on the rocks of the region, the collected data was compared to the published data on the limestone lithology and microfacies of the Gerasa area. The results show that the mosaic tesserae were most likely of local limestone sources, and they agree well with previous research results that examined the source of mosaic tesserae of ancient churches. They might also indicate the appropriateness of the local stones to design the mosaic floors irrespective of whether the churches were built inside or outside the city center. It is likely that Gerasa mosaics at that time were designed by the same mosaicists, or by mosaic products of the same workshop.